Rapidly repeated visual stimulation induces long-term potentiation of VEPs and increased content of membrane AMPA and NMDA receptors in the V1 cortex of cats.

Studies report that rapidly repeated sensory stimulation can evoke LTP-like improvement of neural response in the sensory cortex. Whether this neural response potentiation is similar to the classic LTP induced by presynaptic electrical stimulation remains unclear. This study examined the effects of repeated high-frequency (9 Hz) versus low-frequency (1 Hz) visual stimulation on visually-evoked field potentials (VEPs) and the membrane protein content of AMPA / NMDA receptors in the primary visual cortex (V1) of cats.

Swimming exercise ameliorates insulin resistance and nonalcoholic fatty liver by negatively regulating PPARγ transcriptional network in mice fed high fat diet.

Background: Recent findings elucidated hepatic PPARγ functions as a steatogenic-inducer gene that activates de novo lipogenesis, and is involved in regulation of glucose homeostasis, lipid accumulation, and inflammation response. This study delved into a comprehensive analysis of how PPARγ signaling affects the exercise-induced improvement of insulin resistance (IR) and non-alcoholic fatty liver disease (NAFLD), along with its underlying mechanism.

Methods: Chronic and acute swimming exercise intervention were conducted in each group mice.

Top-down influence of areas 21a and 7 differently affects the surround suppression of V1 neurons in cats.

Surround suppression (SS) is a phenomenon whereby a neuron's response to stimuli in its central receptive field (cRF) is suppressed by stimuli extending to its surround receptive field (sRF). Recent evidence show that top-down influence contributed to SS in the primary visual cortex (V1). However, how the top-down influence from different high-level cortical areas affects SS in V1 has not been comparatively observed.

Suppression of top-down influence decreases both behavioral and V1 neuronal response sensitivity to stimulus orientations in cats.

How top-down influence affects behavioral detection of visual signals and neuronal response sensitivity in the primary visual cortex (V1) remains poorly understood. This study examined both behavioral performance in stimulus orientation identification and neuronal response sensitivity to stimulus orientations in the V1 of cat before and after top-down influence of area 7 (A7) was modulated by non-invasive transcranial direct current stimulation (tDCS). Our results showed that cathode (c) but not sham (s) tDCS in A7 significantly increased the behavioral threshold in identifying stimulus orientation difference, which effect recovered after the tDCS effect vanished.

Modulation of top-down influence affects trafficking of glutamatergic receptors in the primary visual cortex.

Numerous studies indicate that top-down influence plays critical roles in visual perception by enhancing neuronal excitability in the primary visual cortex (V1). The underlying mechanisms are poorly understood. This study examined changes of excitatory glutamatergic markers in the V1 cortex of cat after top-down influence of cortical area 7 (A7) was modulated by transcranial direct current stimulation (tDCS).

Mechanisms of Surround Suppression Effect on the Contrast Sensitivity of V1 Neurons in Cats.

Surround suppression (SS) is a phenomenon that a neuron's response to visual stimuli within the classical receptive field (cRF) is suppressed by a concurrent stimulation in the surrounding receptive field (sRF) beyond the cRF. Studies show that SS affects neuronal response contrast sensitivity in the primary visual cortex (V1). However, the underlying mechanisms remain unclear.

Exercise ameliorates high-fat diet-induced insulin resistance accompanied by changes in protein levels of hepatic ATF3-related signaling in rats.

Purpose: Exercise is an effective way to alleviate insulin resistance (IR). However, the underlying mechanisms remain to be elucidated. Previous studies demonstrated that cardiolipin synthase 1 (CRLS1)/interferon-regulatory factor-2 binding protein 2 (IRF2bp2)-activating transcription factor 3 (ATF3)-adiponectin receptor 2 (AdipoR2)-adaptor protein containing pH domain, PTB domain and leucine zipper motif 1 (APPL1)-protein kinase B (AKT/PKB)-related signaling was closely associated with obesity-induced IR-related diseases, but the correlation between exercise training alleviating obesity-induced IR and the protein levels of hepatic CRLS1/IRF2bp2-ATF3-AdipoR2-APPL1-AKT-related signaling in rats is unknown.

Effects of top-down influence suppression on behavioral and V1 neuronal contrast sensitivity functions in cats.

To explore the relative contributions of higher-order and primary visual cortex (V1) to visual perception, we compared cats' behavioral and V1 neuronal contrast sensitivity functions (CSF) and threshold versus external noise contrast (TvC) functions before and after top-down influence of area 7 (A7) was modulated with transcranial direct current stimulation (tDCS). We found that suppressing top-down influence of A7 with cathode-tDCS, but not sham-tDCS, reduced behavioral and neuronal contrast sensitivity in the same range of spatial frequencies and increased behavioral and neuronal contrast thresholds in the same range of external noise levels. The neuronal CSF and TvC functions were highly correlated with their behavioral counterparts both before and after the top-down suppression.

Exercise ameliorates insulin resistance and improves ASK1-mediated insulin signalling in obese rats.

Increasing evidence reveals that physical exercise is an efficient therapeutical approach in the treatment of insulin resistance (IR) and related metabolic diseases. However, the potential beneficial effects of exercise on insulin resistance and its underlying mechanisms remain unclear. Recent findings elucidated the negative role of ASK1 in repressing the glucose uptake through JNK1-IRS1-Akt signalling in liver.

Suppression of top-down influence decreases neuronal excitability and contrast sensitivity in the V1 cortex of cat.

How top-down influence affects neuronal activity and information encoding in the primary visual cortex (V1) remains elusive. This study examined changes of neuronal excitability and contrast sensitivity in cat V1 cortex after top-down influence of area 7 (A7) was modulated by transcranial direct current stimulation (tDCS). The neuronal excitability in V1 cortex was evaluated by visually evoked field potentials (VEPs), and contrast sensitivity (CS) was assessed by the inverse of threshold contrast of neurons in response to visual stimuli at different performance accuracy.

Characterization of Feedback Neurons in the High-Level Visual Cortical Areas That Project Directly to the Primary Visual Cortex in the Cat.

Previous studies indicate that top-down influence plays a critical role in visual information processing and perceptual detection. However, the substrate that carries top-down influence remains poorly understood. Using a combined technique of retrograde neuronal tracing and immunofluorescent double labeling, we characterized the distribution and cell type of feedback neurons in cat's high-level visual cortical areas that send direct connections to the primary visual cortex (V1: area 17).

Top-down influence affects the response adaptation of V1 neurons in cats.

The visual system lowers its perceptual sensitivity to a prolonged presentation of the same visual signal. This brain plasticity, called visual adaptation, is generally attributed to the response adaptation of neurons in the visual cortex. Although well-studied in the neurons of the primary visual cortex (V1), the contribution of high-level visual cortical regions to the response adaptation of V1 neurons is unclear.

Exercise ameliorates insulin resistance and improves SIRT6-mediated insulin signaling transduction in liver of obese rats.

Physical exercise is essential for the amelioration of insulin resistance (IR). The mechanisms in charge of improved IR, regulated by exercise, are insufficiently studied. Previous research revealed that Sirtuin 6 (SIRT6) - mediated insulin signaling acts a crucial element in hepatic IR.

Anodal and cathodal tDCS modulate neural activity and selectively affect GABA and glutamate syntheses in the visual cortex of cats.

Key Points: The present study showed that anodal and cathodal transcranial direct current stimulation (tDCS) can respectively increase and decrease the amplitude of visually evoked field potentials in the stimulated visual cortex of cats, with the effect lasting for ∼60-70 min. We directly measured tDCS-induced changes in the concentration of inhibitory and excitatory neurotransmitters in the visual cortex using the enzyme-linked immunosorbent assay method and showed that anodal and cathodal tDCS can selectively decrease the concentration of GABA and glutamate in the stimulated cortical area. Anodal and cathodal tDCS can selectively inhibit the synthesis of GABA and glutamate by suppressing the expression of GABA- and glutamate-synthesizing enzymes, respectively.

Heroin exposure and withdrawal differentially influence expression of NMDA receptor NR2 subunits in the prelimbic region of rat medial prefrontal cortex.

It is widely reported that drug addiction involves the strengthening of specific reward circuits through N-methyl-d-aspartic acid receptor (NMDAR)-dependent synaptic potentiation, and several lines of evidence strongly implicate NMDA receptor 2 (NR2) subunits in drug abuse. To explore the potential mechanism of heroin dependence, this study examined changes in the expression levels of NR2 subunits NR2A-D in the prelimbic (PL) region of the medial prefrontal cortex (mPFC) after repeated heroin administration and subsequent abstinence. The conditioned place preference (CPP) test confirmed successful induction of heroin dependence and withdrawal.

[Effect of swimming exercise on MEK and ERK1 phosphorylation level in adipose tissue of insulin resistance rats].

Objective: To investigate the effect of chronic and acute swimming exercise intervention on the mitogen-activated extracellular signal-regulated kinase(MEK) and extracellular signal-regulated kinase 1(ERK1) phosphorylation level in adipose tissues of obesityinduced insulin resistance rats.

Methods: A total of 100 SD rats were randomly divided into control group(n=10) fed with normal diet and high-fat diet group(n=90) fed with high fat diet. After 8 weeks, one third rats(n=30) with upper weight in high-fat diet group were selected and randomly divided into high-fat diet sedentary group(n=10), chronic exercise group(n=10) and acute exercise group(n=10).

[The protective effect of tea polyphenols on chronic alcoholic liver injury in rats].

Objective: To investigate the protective effects and potential mechanisms of tea polyphenols intervention on excess alcohol intake induced liver injury in rats. This study established the animal model of chronic liver injury rats induced by alcohol. Our results will provide experimental evidence for the effects of tea polyphenol on chronic alcoholic liver injury.

Theta-gamma coupling in the prelimbic area is associated with heroin addiction.

The medial prefrontal cortex (mPFC) is implicated in the regulation of drug-seeking behavior, but the specific contributions of the mPFC prelimbic (PL) subdivision and the precise mechanisms underlying heroin abuse remain largely unclear. In the present study, we examined changes in the rhythmic ensemble activity of PL neurons after induction of heroin addiction in rats. Rats were injected daily with saline (control group) or heroin (addiction group) in the light chamber of a light-dark shuttle box, and a video tracking system was used to measure conditioned place preference (CPP) as a sign of addiction.

Green tea polyphenols ameliorate ethanol-induced spatial learning and memory impairments by enhancing hippocampus NMDAR1 expression and CREB activity in rats.

The current research probed into the effects of green tea polyphenols (GTPs) on ethanol-induced spatial learning and memory impairments and inquired the potential molecular mechanism in rats. Thirty 8-week-old male Sprague-Dawley rats were randomly divided into three groups. The control group (control, n=10), ethanol group (ethanol, n=10), and GTPs intervention group (GTP, n=10) received gavage administration of saline, ethanol, and ethanol-GTP solution, respectively, for 8 weeks.

Exercise ameliorates insulin resistance via regulating TGFβ-activated kinase 1 (TAK1)-mediated insulin signaling in liver of high-fat diet-induced obese rats.

Exercise is an effective therapy for insulin resistance. However, the underlying mechanism remains to be elucidated. Previous research demonstrated that TGFβ-activated kinase 1 (TAK1)-dependent signaling plays a crucial character in hepatic insulin resistance.

Axon initial segment plasticity accompanies enhanced excitation of visual cortical neurons in aged rats.

Recent studies have indicated that the structure of the axon initial segment (AIS) of neurons is highly plastic in response to changes in neuronal activity. Whether an age-related enhancement of neuronal responses in the visual cortex is coupled with plasticity of AISs is unknown. Here, we compare the AIS length and the distribution of Nav1.

Exercise induced improvements in insulin sensitivity are concurrent with reduced NFE2/miR-432-5p and increased FAM3A.

Aims: Little is known regarding whether the NFE2/miR-423-5p and FAM3A-ATP-Akt pathway in liver mediates exercise allured alleviation of insulin resistance connected with diet-induced obesity. This research inquired the influence of exercise on liver insulin sensitivity and whole body insulin resistance in high-fat diet fed rats.

Materials And Methods: Forty male Sprague-Dawley rats at seven-week-old were assigned to four groups at random: standard diet as normal control group (NC, n = 10), high-fat diet group (HFD, n = 10), high-fat diet with chronic exercise intervention group (HFD-CE, n = 10) and high-fat diet with acute exercise intervention group (HFD-AE, n = 10).

Changes in GABAergic markers accompany degradation of neuronal function in the primary visual cortex of senescent rats.

Numerous studies have reported age-dependent degradation of neuronal function in the visual cortex and have attributed this functional decline to weakened intracortical inhibition, especially GABAergic inhibition. However, whether this type of functional decline is linked to compromised GABAergic inhibition has not been fully confirmed. Here, we compared the neuronal response properties and markers of GABAergic inhibition in the primary visual cortex (V1) of young adult and senescent rats.